Friction-controlled pawl-and-ratchet-operated shock absorber for automobiles and like vehicles



l Mw., 24l 1925. M5628@ F. N. ',SFRAGUE FRICTION CONTROLLED PAWL AND RATCHET OPERATED SHOCK ABSORBER FOR AUTOMOBILES AND LIKE VEHICLES Filed April l5, 1924 2 Sheets-Sheet l -sHocK y s E Shee ts-Sheet F. SPRAGUE FRIGTION' CONTROLLED AwL AND RATGHET OPE ABso MOBILES AND LIKE v Nov. 24l 1925- RATED EHI CL RBER FOR AUTO Filed Apri Sli Palmi@ ov, 24, u

FRANK N'. SPRAG'UE, 0F HOLYOKE, COLOBAD.

FRICTIUNNTROLLED FAWL-AND-RATCHJET-GPERATED SHOCK ABSORBER Fm .ELUTMUBILES ANB LIKE VEHICLES.

appneation mea april i5, naar. serial no. voegen.

To all 'whom t may coiwern:

Be it known that I, FRANK N. SPRAGUE, a citizen ci the United States vof America, residing at Holyoke, county of Phillips, and State of Colorado, have invented a. new and useful Friction-Controlled Fawl-and-ldatchet-Gperated Shock Absorber for Automobiles and like Vehicles, ot which the following is a specication.

My invention relates to improvements in friction controlled, pawl and ratchet operated shock absorbers for automobiles and like vehicles. Y

rllhe object ot my invention is to provide a friction controlled and pawl and ratchet operated mechanism which is adapted to be connected to the side bar of a car and4 with the side spring, in such manner that the' mechanism is actuated by the action of .the side spring to yinstantly and gradually checlr the rebound of the -spring and thus eliminate the violent vupward throw of the car body.

Further to provide a shock absorber comprising a housing adapted to be. rigidly secured to the side bar oi a car, in which is mounted a friction controlled, pawl and ratchet, operated mechanism, said pawl and ratchet mechanism being actuated by a lever arm, which is .connectedv to the side spring by a connecting rod, whereby the spring action L,is transmitted to the lever arm, the upward movement ot said arml under compression ot' the spring causing the pawls to ride over the ratchets, while the rebound of the spring causes a pawl tofengage a triction controlled ratchet ring, thereby to.ab.

sorb the shock of the rebound. r v

rlhese objects are accomplished by the mechanism illustrated in theaccompanying drawings in which: A'

Figure 1 is a side view illustrating the application of the improvedshock absorber l to the iront end of a Side springtorm of automobile, the spring and a. portion only ot the side bar bein shown.

Figure 2 is a horizontal'sectional viewfull size-through the shoclr absorber.

Figure 3 is a central vertical longitudinal sectional view of the same.

Figure 4ris a bottom vview thereof.

Figure 5 is a sectional yview through the side bar ot an automobile showing the shock absorber and the manner in which it is secured to the side bar'.

Figure 6 is a view of the rear side oi." the shock absorber.

Figure 7 is a side View ot the pawl-bloclr.

Figure 8 is an edge view ot the sanae Figure 9 is an edge view of the brake band.. l

Figure 10 is a top view or the outer end portion ot the lever arm, showing the manner ot its connection with the upper end of the adjustable bar which connects the said lever arm with the side spring of the automobile. y

Figure 11 is a plan view ot the anchor plate to which the lower end ol.E the adjustable bar is connected; and,

Figure 12 is a view of a modified torni ot brake 4band-tightening screw.

Referring to the accompanying drawings:

The numeral 1, indicates the forward por-V tion of the side bar of an automobile; 2, the semielliptie side spring, the forward end Ot which is connected to a bolt 3 in the torward end ofthe side bar, and its rear end `to a shackle, d which is pivotally connected to the side bar; and 5, the front axle to,

which the spring 2 is clamped in the usual manner by lll-bolts 6; all ot the above named parts being of common construction.

lin carrying out my invention, li employ a housing 7 which' is secured to the side bar 1 at a point either forward or rear ot the axle, and which is constructed in the following manner: This housing is cylindrical in form and is closed on its "front side by an integral head 8, having a central hub 9, while its rear kend is closed by a capv 10 having a central hub 11, the said cap bein secured to the housing by cap screws 12, w ich are screwed into threaded holes in enlargements or ribs 13 formed on the inner wall of the housing. 'llhe hub 11 ot the cap is formed with an integral upward extension 14; having a horizontal head 15 on its upper end which is adapted to bear against the side bar 1,'and a cap bolt 16 is passed through a hole in the side bar and screwed into a threaded hole 17 in the said extension 14. A pairoi lugs 18 are termed on the cap 10 below the hub 11, and the ends ot these u s formed to bear against the tace of the si e Miti bar and also against its under edge, as shown in Figure 5, so'that when the cap bolt lugs which extend under the side barwill' prevent a turning movement of the housing on the side bar.

Within the housing is mounted a pair of spaced disks 19 and 20, having hubs 21,v

which pass through the disks and through the ring. l

A shaft 27 is mounted in the hubs 21 of the disks 19 and 20; and one end of this shaft extends out beyond the hub of the disk 20 for the reception of a lever arm 28 to be presently described. A circular block 29, which constitutes a pawl-holding'block, is keyed to the shaft 27, and is of slightly less diameter than the circle described by the points of the ratchet teeth 25, and this block is of slightly less thickness than the space between the disks 19 and 20, as shown in Figur-e2.

Four equi. distant holes 30 extend into the block a suitable distance .from its peripheral face, and these holes constitute spring pockets, and their axes are slightly tangent to the axial center of the block.

Transverse slots 31 arel also formed in the block so as to intersect the pockets 30, but the slots 31 are of less width than the diameter of the pocket,and also of less depth than the pocket, and the thickness ofv the block is reduced between the slots to form recesses 32 in the opposite sides of the block, which permits of a supply of oil being placed in the chamber formed by the disks 19 and 20 and` the ratchet ring 24, as will be referred to.

A coil spring 33 is placed in each of the pockets 30` and a pawl 34 is inserted in each slot 31,. These pawls are in the form of 'lat plates which titslidably in the slots 31, and the length of each pawl equals the thickness of the block 29, and their outer ends are chisel-edged to correspond `to the ratchet teeth 25. The pawls 34 are of less width than the depth of the slots 31, and they are held in resilient engagement withthe ratchet teeth 25, by the coil springs 33 against which they are seated.

An uneven number of ratchet teeth is formed in the ring 24, and as the axes of the pawls 34 are slightly tangent to the axial center of the ratchet block 29, the ratchetengaging point of each pawl will be in radial line with the axial center of the said ratchet block. By this .arrangement one of hereinafter the pawls is in engagement with a tooth, the

next pawl to the left is one-fourth of the length of the tooth out of engagement, the

next pawl is onehalf of the length of a tooth out of engagement, and the last pawl is three-fourths of the length of a tooth out of engagement, as clearly shown in Figure 3.

By this arrangement of the pawls, one of` them is always in position to engage a ratchet tooth, on the operative movement ot' the ratchet block, thus reducing the lost motion of the block to a minimum.

Around the outer wall of the ratchet ring 24 is placed a brake lining 35, ofthe style'ot' materialjin common use for such .pur oses, and the lining is surrounded by a resllient brake band 36, both the band and the lining lying between the marginal edges of the disks 19 and 20, as shown in Figure2.

The brake band is a divided band, and the free ends thereof arebent outwardly at right angles to form ears 37, which are apertured; and these ears are reinforced by angle strips 38 which are brazed .to the ears and to the band, and are also apertured to coincide with the ears.y At the opposite point on the brake band from the ears 37, stops or abutments 39 are formed by cutting two parallelslits in the band, and a transverse slit connecting the two parallel slits, and then bending the two port-ions out at right angles to form the said abutments 39, as shown in Figures 3 and 9. i

One of the enlargements or ribs 13, on the inner wall of the housing 7, is formed with an'nwardly projecting lug 40, which is adapted to tit in between the two abutments 39, and thus hold the brake band at this point against rotary movement. At an opposite point from the lug 40, the circular wall ofthe housing 7 is formed with an .abrupt transverse inwardly projecting step 41, and a recess V42 is formed in the sai circular wall,l which'extends into the said step, thereby forming a wall 43 in the step which is provided with an aperture 44 in axial line with the apertures inthe ears 37 of the brake band.

A specially constructed screw S, comprising an elongated head 45, and a shank 46 the end portion, only, of whichv is threaded, is passed through the hole 44 in the wall 43 and through the apertures in the .ears37 ot the brake band, a coil spring 47 Vbeing first placed upon the shank of the screw so as to lie between the head of the screw and the adjacent ear 37 of the brake band, after '16,)

thereb exerting a resilient pressure against the said ear, and at the same time, the nut 49 which cannot rotate, 1s drawn inward vagainst the spring 48, thereby exerting a resilient pressure against the adjacent ear 37, and the spring pressure on the two ears 37 causes the brake band to grip the brake lining 35 with the necessary pressure for the purpose' intended.` When the screw S is turned to give the necessary gripping power to the brake band, the said screw is held against rotation by a set screwV 50, which is screwed into a threaded aperture in the step wall43, and against the elongated head of the screw S, as shown in Figure 3; and any rotary slipping movement of the band is prevented by the engagement of the brake band Ystops 39 with the lug 40 onl the housing wall, as previously mentioned.

The lever arm 28` is keyed to the outer end portion of the shaft 27, and is held upon t-he shaft by a nut 2A, which is screwed upon the reduced and threaded end of the shaft, and against the hub of the' arm.

The lever arm is bent inward and then in p a straight rearward direction, and terminates in a' short right-angle bend 51 in line with the forward axle 5. One end` of a: spring coil 52 is passed through a hole in the bend 51 and is given a right-angled bend 53, and the end of the bend 53 is threaded and is passed throughva hole 54 in the end' portion ofthe arm and receivesa nut 55.-

The other end of the spring coil 52, is passed through a right-angled bend 56, on the upper end of a vertical bar 57, and is then bent at right angles and passes through a hole in the said' bar, and receives a nut V58. The bar 57. is substantially V- shaped in cross section, and a second bar 58, rests in and-is adjustably bolted to the said bar 57, and its lower end terminates'in angles, as shown at 63 in Figure 11, and is passed through the other wing of the plate 61 and receives a nut 64. The bars 57 and 58 are adjusted as to length so that when they connect the arm 28, and the spring 2, the arm 28 will normally lie in a horizontal position. The spring coils 52 and 60 will cushion the initial thrust under the compression and rebound of the spring 2, and

thusminimize the strain on the parts. l. The

bars 57 and 58 constitute a connecting rod C.

A packing disk 65 is placed over the end ot the hub 11- of the housing cap 10an`d is held in place by a cap 66 which tits tightly over the said hub. A packing ring 67 is placed over the end of the hub 9 of 'the housing and is held in place by a cap 68 disks 19 and 20 and ratchetring 24, and

thus keep the pawl and ratchet mechanism thoroughly lubricated." y f i In Figure 12 I show ascrew S1, which can be used'in place of the screw S, particularly when the screw is arranged on the lower side of the housing, as inFigure 3. IThe elongated head 72of 'this s'c'reav is formed with an annularL groove 73 in Vvwhich a pack ing ring 74` is 'placed;-which ring is designed to fit so tightly inthe hole of the' wall 43 as to prevent' leakage of oil from the houslng, and also the looseninwgr of the screw is used, with. Y

In practice, the improved shock absorber is arrangedas shown Ain Figure 1, and when the car is in motion, compression' of the spring, by the movement of the axle toward the car body, Vcauses an upward movement of the lever arm 28, by means of the connecting rodv C, Aand the p awl block 29 is turned toward the left, thereby causing the pawls 34 to ride over the ratchet teeth of the ring 24, without imparting any-movement to the said ring, but instantly `upon the rebound of the spring, and consequently of the body, one of the pawls 34 engages a ratchet tooth the set screw -50 isl dispensed '25, and the ring is thereby turned against the rictional resistance imposed bythe grip of the brakev band 36 upon the brake lining 35, and the shock of the rebound is thereby absorbed. By the arrangement of pawls here'inbefore described, one pawl is always in position to engage a ratchetV tooth with practically no lost. movement of the pawl block, so that the force of the rebound is instantly checked. The .brake hand can be caused to grip the brake lining under pressure that will impose a friction-al resistance to the movement of the ratchet ring suitable to meet varyingload conditions, it being apparent that with a light load, the tension on the brake band should be less than when the conditions are the reversew The `pawl and lratchet mechanism 'acts so quickly lthat even screw by vibration, and when this form of. 'i

ioc-

CAD

the ordinary vibratory movement of the car/ the.' action of the spring l2 and the character of the mechanism asa whole is such asto enable it'to meet the varying road ande-load conditions to which the car may be sub-V jected. p

Having described my invention, what l claim as new and desire to secure by Letters Patents is:

l. The combination with the, side bar and side spring of an automobile, offa housing on said side bar, disks rotatably mounted in said housing, ,and a ring rigidly'clamped between said disks having internal ratchet teeth, abrake band secured to the housing and extending around said ring. the ends of said band terminating in apcrtured cars, a screw extending loosely through said ears having an elongated head which is mounted in an aperture in the circular wall of said housing, a fixed nut on the end of said screw, a coil spring on said screw interposed between the nut and the adjacent ear, -aeoil spring on the screw interposed between the other ear and the head of said screw, whereby said screw when turned causes said brake band to grip said ringwith a resilient pressure, a shaftaxially mounted in said housing, acarrier keyedv to said shaft having pawls for engaging said ratchet teeth, an arm on said shaft, and a rod connecting said arm and said side spring.

2. In a shock absorber of the characterr described, the combination with the side bar and Side spring of an automobile, of a hu's'- ing secured to said sidebar having an end Wall, a cap on the open. end of said housing and an, axial hub on said cap and said end wall, disks in said housing having hubs which lit in the aforesaid hubs7 an internally toothed ratchet ring secured betweensaid disks, a shaft mounted in said disk hubs, a circular block keyed to said shaft having spring-actuated pawls for engaging the teeth of said ratchet ring, 'a'brake lining surrounding said ratchet ring, a resilient brake band surrounding said brake lining, means Whereby said brake band is caused to grip said brake liningwith regulated resilient pressure, a lever arm on one end of said shaft and a rod connecting the end of said arm and said side spring.

3. 1n a shock absorber of the character described, the combination with-the side bar and side spring of an automobile of a housing secured to said Side bar, disks in 4said housing having axial hubs mounted in the ends of said housing, an internally toothed ratchet. ring secured between said disks,

a' shaft mounted in said hubs, a circular block keyed yto said shaft, having spring actuated pawls mounted in slots therein which engage .said ratchet teeth, said block being recessed on its opposite sides to form air pockets, one' of said disks having an oil hole therein, and normally closed oil holes being. formed 'in one end of said housing, a brake band surrounding said ratchet ring, means whereby the brakeband is caused to grip the ratchet ring with a regula-ted re silient pressure, a lug-on said housing wall and stops on said brake band which engage said lug to prevent axial movement of the brake band, a lever arm on said shaft and a rod connecting the free end of said arm with the side sprine.

4. In a device of the cha acter described, the combination with the side bar and side spring of an automobile; of a circular housing, a cap bolted upon kone end of said housing, an abutment on said cap above its axial center adapted to bear against the said side bar, abutments on said cap below its axial center adapted to hearagainst the front face of said side bar and also against its under side and a bolt which passes through said side bar and is threaded to the upper abutment, a'friction-controlled paWl and ratchetactuated mechanism in said housing, and means connecting said pawl and ratchet mechanism with the side spring, whereby the' action of said spring is transmitted'to said mechanism. i In testimony whereof l aflix my signature.

FRANK N. SPRAGUE'. 

